In the field of low-pressure casting of aluminum wheels, a water cooling mold has become a development direction for future mold development, while water spot cooling will be the key point of the future development direction. Facing various changes of wheel structures, water spot cooling shall not only be applied to side mold cooling, but also be applied to bottom mold cooling. Especially for large-size wheel types, only depending on side mold cooling, it is difficult to ensure the quality of spokes. Therefore, it will be imperative to develop a device capable of achieving water spot cooling of a bottom mold. Moreover, the developed device can never be limited by product structures, and must be suitable for all kinds of products so as to ensure the popularization and the application of water spot cooling in bottom mold cooling.